JP3443780B2 - Method for producing phenoxy polyalkylene glycol acrylate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing phenoxypolyalkylene glycol acrylate, and more particularly to a method for producing phenoxypolyalkylene glycol from polyethylene glycol monophenyl ether or polypropylene glycol monophenyl ether and acrylic acid. The present invention relates to a method for producing a glycol acrylate. [0002] The phenoxypolyalkylene glycol acrylate obtained by the present invention is used as a reactive diluent for paints, printing inks, etc., which is cured by active energy rays such as ultraviolet rays and electron beams. [0003] Conventionally, phenoxyethyl acrylate and phenoxypropyl acrylate have good compatibility with various resins. Therefore, the reaction of paints, printing inks, etc., which are cured by active energy rays such as ultraviolet rays or electron beams. It has been used as a functional diluent. However, the peculiar odor is a problem in the workplace environment at the use site of ink, paint and the like. As a method of reducing this odor, phenoxypolyalkylene glycol acrylates having a longer oxyalkylene group chain have been used. However, in this case, if the length of the oxyalkylene chain is not sufficient, the odor remains. On the other hand, if the length of the chain is long, the odor is reduced but the viscosity is increased, and the performance as a diluent is reduced. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a polyoxyalkylene glycol acrylate having a low odor without lowering the performance as a diluent. The present inventors have made intensive studies on the odor of phenoxypolyalkylene glycol acrylate, and as a result, have solved this problem by esterifying a specific phenoxypolyalkylene glycol with acrylic acid. did. That is, the present invention relates to a method for producing a phenoxypolyalkylene glycol acrylate by an esterification reaction between polyalkylene glycol monophenyl ether and acrylic acid.
Production of phenoxy polyalkylene glycol acrylate, characterized by using polyalkylene glycol monophenyl ether obtained by adding 1.1 to 5 moles of ethylene oxide or propylene oxide to a mole and then distilling low-boiling substances by distillation under reduced pressure. Is the way. DETAILED DESCRIPTION OF THE INVENTION In the present invention, phenoxypolyalkylene glycol as a raw material is obtained by adding ethylene oxide or propylene oxide (hereinafter, both are simply referred to as alkylene oxide) to phenol, and then distilling low-boiling substances under reduced pressure. Is distilled off. The average addition amount is 2 to 5 mol, preferably 2 to 3 mol. In this addition reaction, a monoalkylene oxide adduct may be produced simultaneously. This is because phenoxyethanol and phenoxypropanol, which are monoalkylene oxides, have their own uses and also have the advantage of co-production. Accordingly, the amount of alkylene oxide added, ie, the amount used, in the reaction for producing the phenoxypolyalkylene glycol used in the present invention is 1.1 to 5 mol, preferably 1.3 to 3 mol, per 1 mol of phenol. When the amount of alkylene oxide added is less than 0.1 mol, the yield of phenoxypolyalkylene glycol obtained after distilling off low-boiling substances is small, and when it is more than 5 mol, the viscosity of the final product becomes high, and As the performance is reduced. In the addition reaction, an alkali catalyst such as sodium hydroxide or potassium hydroxide is added to phenol, and the inside of the system is replaced with nitrogen, and then alkylene oxide is gradually added. The reaction temperature is usually maintained at 100 to 200 ° C. After completion of the reaction, the catalyst is neutralized and separated by filtration or adsorbed on an adsorbent to separate the catalyst. Sulfuric acid as a neutralizing agent,
Mineral acids such as hydrochloric acid, nitric acid, and phosphoric acid, or organic acids such as acetic acid, lactic acid, and benzoic acid can be used. As the adsorbent, a synthetic adsorbent having an alkali adsorption property is used. From the phenol alkylene oxide adduct from which the catalyst has been removed, low-boiling substances are separated by distillation under reduced pressure.
The low-boiling products to be separated are mainly monoalkylene oxide adducts, and a precision distillation column with the required number of stages is used so that the content of the monoalkylene oxide adduct in the distillation residue is 5% or less, and usually 10 columns. A degree of distillation column is used.
The distillate having a low boiling point is used for other purposes as necessary as phenoxyethanol or phenoxypropanol. The content of monoalkylene oxide in the obtained residual liquid (phenoxypolyalkylene glycol) is measured by gas chromatography. Monoalkylene oxide adduct content is 5% or less, preferably 1%
The odor of the final product increases when it exceeds 5%. The phenoxypolyalkylene glycol from which low-boiling substances have been distilled off is reacted with acrylic acid in the presence of a dehydrating azeotropic solvent, a polymerization inhibitor and an acid catalyst. The amount of acrylic acid used for the esterification is 1 to 3 mol per 1 mol of phenoxypolyalkylene glycol. If it is less than 1 mol, unreacted glycol remains, and if it is 3 mol or more, removal of unreacted acrylic acid is troublesome. Examples of the dehydration azeotropic solvent used in the esterification reaction include organic solvents such as benzene, toluene, hexane, and cyclohexane. The amount of the solvent used is based on the total amount of the raw material phenoxypolyalkylene glycol and acrylic acid. , 10-200% by weight. As the polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether (MEHQ) and the like are used, and the amount of the polymerization inhibitor used is 0.01 to 1%, preferably 0.1 to 0.5%.
% Range. In addition, the presence of a small amount of molecular oxygen is effective in preventing the polymerization of acrylic acid as a raw material and the resulting ester,
A small amount of air is continuously blown into the reaction vessel. The catalyst used in the esterification reaction is sulfuric acid,
Examples include benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid and the like. These catalysts are used in an amount of 1 to 10% by weight, preferably 2 to 6% by weight, based on the starting glycol. The esterification reaction is carried out at a temperature at which the acryloyl group does not undergo thermal polymerization, generally in the range of 80 to 140 ° C.
This is performed while separating water from the reflux pipe. If the temperature is lower than 80 ° C., a long time is required for the reaction. During the reaction, molecular oxygen, typically air, is continuously blown into the reaction system to prevent polymerization. The reaction time is affected by the amount of the catalyst and the reaction temperature, but is generally about 3 to 20 hours until the distillation of water stops. After completion of the reaction, the reaction solution is neutralized with an aqueous alkali solution, and the aqueous layer is separated to remove unreacted acrylic acid and catalyst. The solvent is distilled off by heating and stirring at about 60 ° C. under reduced pressure from the obtained oil layer, and the remaining liquid is filtered to obtain a phenoxypolyalkylene glycol acrylate with low odor. EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Into a 3 l stainless steel autoclave equipped with a stirrer, 941 g of phenol and 3 g of potassium hydroxide, which had been heated and melted in advance, were charged, and the air in the autoclave was replaced with nitrogen. While maintaining at 160 ± 5 ° C., was gradually introduced over about 2 hours. After completion of the reaction, the mixture was cooled, a synthetic adsorbent (Kyowa 700SN, manufactured by Kyowa Chemical Industry Co., Ltd.) was added, and the mixture was stirred for 1 hour and filtered. 1,500 g of the filtrate was charged into a 2-liter distillation flask,
A 10-stage Aldershaw distillation column was set and distillation was performed at a pressure of 10 mmHg. When the temperature at the top of the column reached 130 ° C., the distillation was stopped, and a phenoxypolyalkylene glycol having a hydroxyl value of 300 was obtained as a residual liquid (A). This residual liquid (A)
The amount of phenoxyethanol in the mixture was analyzed by gas chromatography and found to be 0.5%. In a four-necked flask equipped with a reflux condenser with a drain tube, a thermometer, an air blowing tube, and an airtight stirrer, 187 g of the above-mentioned residual liquid (A), 94 g of acrylic acid, 270 g of toluene,
0.3 g of hydroquinone monomethyl ether (MEHQ) and 6 g of p-toluenesulfonic acid were charged, and heated and stirred on an oil bath while blowing air. Water starts to distill at a liquid temperature of 105 ° C, and after about 5 hours
Distillation of water was completed at 125 ° C. The esterification reaction rate calculated from the amount of distilled water was 99%. An aqueous alkaline solution was added to the esterified solution, mixed, and allowed to stand. Then, p-toluenesulfonic acid and excess acrylic acid were extracted into the aqueous layer and separated from the oil layer. Toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer. The residue was filtered to obtain 220 g of phenoxypolyalkylene glycol acrylate. Table 1 shows the results of an odor test and viscosity measurement performed by 20 persons on this liquid. Example 2 The same reactor as in Example 1 was charged with the same amount of molten phenol and potassium hydroxide, and at the same temperature, 1140 g of ethylene oxide was added.
Was introduced over 2 hours. After completion of the reaction, the mixture was cooled and
The adsorption treatment was performed in the same manner as described above, followed by filtration. The filtrate (1,500 g) was distilled under the same conditions as in Example 1 to obtain 1,300 g of a residual liquid (B). The obtained phenoxy polyethylene glycol had a hydroxyl value of 260 and a phenoxyethanol content of 0.4%. In a four-necked flask equipped with a reflux condenser equipped with a drain tube, a thermometer, an air blowing tube, and an airtight stirrer, 216 g of the above residual liquid (B), 94 g of acrylic acid, 300 g of toluene,
0.4 g of MEHQ and 6 g of p-toluenesulfonic acid were charged and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 5 hours, and the esterification reaction rate calculated from the amount of distilled water was 99%. An alkaline aqueous solution was added to the esterified solution, mixed and stirred as in Example 1, and toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 250 g of phenoxy polyethylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. Example 3 The same molten phenol and potassium hydroxide as in Example 1 were charged, and 870 g of propylene oxide was introduced at a liquid temperature of 120 ± 5 ° C. over about 6 hours. After completion of the reaction, adsorption treatment and filtration were performed in the same manner as in Example 1. The filtrate (1,500 g) was distilled under the same conditions as in Example 1. When the temperature at the top of the column reached 128 ° C., the distillation was stopped to obtain 800 g of a residual liquid (C). The obtained phenoxy polypropylene glycol had a hydroxyl value of 258 and a phenoxypropanol content of 0.6%. In a four-necked flask equipped with a reflux condenser with a drain tube, a thermometer, an air blowing tube, and an airtight stirrer, 218 g of the above-mentioned residual liquid (C), 94 g of acrylic acid, 300 g of toluene,
0.4 g of MEHQ and 6 g of p-toluenesulfonic acid were charged and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 10 hours, and the esterification reaction rate calculated from the amount of distilled water was 97%. An alkaline aqueous solution was added to the esterified solution in the same manner as in Example 1, mixed, and allowed to stand. Toluene was distilled off at 60 ° C. under reduced pressure while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 250 g of phenoxy polypropylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. Comparative Example 1 In the same manner as in Example 1, 1800 g of a phenoxy polyethylene glycol filtrate was obtained. However, the amount of ethylene oxide introduced was 9
30 g. This had a hydroxyl value of 300 and a phenoxyethanol content of 25%. In a four-necked flask equipped with a reflux condenser equipped with a drain tube, a thermometer, an air blowing tube, and an airtight stirrer, 187 g of the filtrate obtained above, 94 g of acrylic acid, 281 g of toluene,
0.3 g of MEHQ and 6 g of p-toluenesulfonic acid were charged and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 5 hours, and the esterification reaction rate calculated from the amount of distilled water was 99%. An alkaline aqueous solution was added to the esterified solution as in Example 1, mixed and allowed to stand. Toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 225 g of phenoxy polyethylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. Comparative Example 2 A phenoxypolyethylene glycol filtrate 20 was prepared in the same manner as in Example 1 except that the introduced amount of ethylene oxide was 1230 g.
50 g were obtained. Its hydroxyl number was 260 and the phenoxyethanol content was 10%. In a four-necked flask equipped with a reflux condenser equipped with a drain tube, a thermometer, an air blowing tube and an airtight stirrer, 216 g of the filtrate obtained above, 94 g of acrylic acid, 310 g of toluene,
0.4 g of MEHQ and 6 g of p-toluenesulfonic acid were charged, and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 5 hours, and the esterification reaction rate calculated from the amount of the distilled water was 99%. An alkaline aqueous solution was added to the esterified solution and mixed as in Example 1, and the mixture was allowed to stand. Toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 245 g of phenoxy polyethylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. Comparative Example 3 The amount of molten phenol was 758 g and the amount of ethylene oxide introduced was 1410
In the same manner as in Example 1 except for the amount of g, 2050 g of a filtrate of phenoxy polyethylene glycol was obtained. Its hydroxyl value is
At 208, the phenoxyethanol content was 1.5%. In a four-necked flask equipped with a reflux condenser with a drain tube, a thermometer, an air blowing tube and an airtight stirrer, 187 g of the filtrate obtained above, 94 g of acrylic acid, 281 g of toluene,
0.3 g of MEHQ and 6 g of p-toluenesulfonic acid were charged and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 5 hours, and the esterification reaction rate calculated from the amount of distilled water was 99%. An alkaline aqueous solution was added to the esterified solution as in Example 1, mixed, allowed to stand, and toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 225 g of phenoxy polyethylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. Comparative Example 4 A filtrate of phenoxy polypropylene glycol was prepared in the same manner as in Example 3 except that the amount of propylene oxide introduced was 1220 g.
1900 g was obtained. Its hydroxyl value was 260 and phenoxypropanol content was 21%. In a four-necked flask equipped with a reflux condenser equipped with a drain tube, a thermometer, an air blowing tube and an airtight stirrer, 216 g of the filtrate obtained above, 94 g of acrylic acid, 300 g of toluene,
0.4 g of MEHQ and 6 g of p-toluenesulfonic acid were charged and heated and stirred on an oil bath while blowing air. The distillation of water was completed in about 12 hours, and the esterification reaction rate calculated from the amount of distilled water was 97%. An alkaline aqueous solution was added to the esterified solution, mixed and stirred as in Example 1, and toluene was distilled off under reduced pressure at 60 ° C. while blowing air into the obtained oil layer.
The residual liquid was filtered to obtain 250 g of phenoxy polypropylene glycol acrylate. The results of the odor test and the viscosity measurement are shown in Table 1. [Table 1] * Judgment of odor (by 20 people) None: Feel unpleasant odor 0 little: 〃 4 strong: 〃 20 [Effect of the present invention] Average addition of alkylene oxide as phenoxy polyalkylene glycol as raw material according to the present invention A phenoxypolyalkylene glycol acrylate having an appropriate viscosity and no odor can be obtained by using a compound having a number of 5 or less and substantially removing a monoalkylene oxide adduct by vacuum distillation, and using this as a diluent. The problem of odor at the time of using the used ink and paint is eliminated.

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Claims (1)

(57) [Claim 1] In a method for producing a phenoxy polyalkylene glycol acrylate by an esterification reaction from polyalkylene glycol monophenyl ether and acrylic acid, 1.1 to 5 moles per 1 mole of phenol A method for producing phenoxypolyalkylene glycol acrylate, characterized by using a polyalkylene glycol monophenyl ether obtained by adding ethylene oxide or propylene oxide of Example 1 above and distilling off low-boiling substances by distillation under reduced pressure.